EDAC/mpc85xx: Include required of headers directly

A subsequent commit to cleanup powerpc's asm/prom.h leads to build
errors in mpc85xx_edac.c due to missing headers. Include all required
headers directly to avoid the build failure.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/edac/mpc85xx_edac.c

@@ -24,6 +24,8 @@
 
 #include <linux/of_platform.h>
 #include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
 #include "edac_module.h"
 #include "mpc85xx_edac.h"
 #include "fsl_ddr_edac.h"